Struggling With Maths

[bald eagle]

help required, please
4/7 divided by 21/24 would ppciate some help and explanation, please
Thank you

[pixie373]

To divide, turn the second one upside down and multiply, so
4/7 x 24/21 is 12 x24 /21
which is 288/21 or 13.71

[bald eagle]

Thank you for your help pixie
kind regards

[pixie373]

Sorry
96/147 is 0.65.

[Psybbo]

Well done, pixie

[Grimaldi]

If you divide by a fraction, simply invert the numerator and denominator, and multiply. This means that if you divide by a (denominator) less than 1, you actually achieve a sum greater than the original numerator.
In this case, the divisor/denominator is 21/24, or 7/8. So the calculation is 4/7 times 8/7, or 32/49, ie 0.65.
There are very few common factors in the problem as stated, if the student is not familiar with converting fractions to decimals. It seems to me it would have been much simpler as 4/7 divided by 24/21, which would work out at 4/7 x 7/8, or 1/2. You will note this is greater than 4/7.

[factor-fiction]

If it's a school work question the answer required will almost certainly be 32/49.

[Peter Pedant]

.

This fundamental arithmetic - altho the kidz are meant to understand 'why', we were just taught rules.
a) multiply two fractions - multiply top with top and bottom with bottom

d) divide two fractions - turn over the second one and then multiply top with opt and bottom with bottom.

no one bothered to tell us what the rationale was - or even if it fitted in with other rules (it does).
This is just how they taught fundamental arith in the early sixties....

21/24 isnt in its lowest terms ( divide by three - it is 7/8)

and the answer is 32/49 ths I think


Pixie's is the same and is not in the lowest terms
divide top and bottom by three
we used to call this cancelling - I used to love doing it !

and also we were not encouraged to express as a decimal as the q was posed as a fraction.

( problem as always - the teacher comes up with all sorts of rules and the child (moi) thinks christ where did that come from ?)

The best teacher's comment in all this was -
'Your father has not understood the problem....'

[factor-fiction]

I just demonstrate with simple numbers initially- eg 1/2 divided by 1/2 must equal 1 and is the same as 1/2 multiplied by 2. Similarly 6 divided by 2 is the same as 6 multiplied by 1/2 (i.e. 3)

[koala13]

answer is 32/49...............4/7 multiplied by 24/21 is way to calculate answer